sulogin: use common password-checking routine.

This needed some extensions correct_passwd() function,
which got renamed ask_and_check_password() to better describe what it does.

function                                             old     new   delta
ask_and_check_password_extended                        -     215    +215
ask_and_check_password                                 -      12     +12
vlock_main                                           394     397      +3
sulogin_main                                         494     326    -168
correct_password                                     207       -    -207
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 1/1 up/down: 230/-375)         Total: -145 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 6 insertions, 37 deletions

diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index 65e638489..2a2909937 100644
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -14,24 +14,12 @@
 #include "libbb.h"
 #include <syslog.h>
 
-//static void catchalarm(int UNUSED_PARAM junk)
-//{
-//	exit(EXIT_FAILURE);
-//}
-
-
 int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int sulogin_main(int argc UNUSED_PARAM, char **argv)
 {
-	char *cp;
 	int timeout = 0;
 	struct passwd *pwd;
 	const char *shell;
-#if ENABLE_FEATURE_SHADOWPASSWDS
-	/* Using _r function to avoid pulling in static buffers */
-	char buffer[256];
-	struct spwd spw;
-#endif
 
 	logmode = LOGMODE_BOTH;
 	openlog(applet_name, 0, LOG_AUTH);
@@ -62,43 +50,24 @@ int sulogin_main(int argc UNUSED_PARAM, char **argv)
 		goto auth_error;
 	}
 
-#if ENABLE_FEATURE_SHADOWPASSWDS
-	{
-		/* getspnam_r may return 0 yet set result to NULL.
-		 * At least glibc 2.4 does this. Be extra paranoid here. */
-		struct spwd *result = NULL;
-		int r = getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result);
-		if (r || !result) {
-			goto auth_error;
-		}
-		pwd->pw_passwd = result->sp_pwdp;
-	}
-#endif
-
 	while (1) {
-		char *encrypted;
 		int r;
 
-		/* cp points to a static buffer */
-		cp = bb_ask(STDIN_FILENO, timeout,
-				"Give root password for system maintenance\n"
-				"(or type Control-D for normal startup):");
-		if (!cp) {
+		r = ask_and_check_password_extended(pwd, timeout,
+			"Give root password for system maintenance\n"
+			"(or type Control-D for normal startup):"
+		);
+		if (r < 0) {
 			/* ^D, ^C, timeout, or read error */
 			bb_info_msg("Normal startup");
 			return 0;
 		}
-		encrypted = pw_encrypt(cp, pwd->pw_passwd, 1);
-		r = strcmp(encrypted, pwd->pw_passwd);
-		free(encrypted);
-		if (r == 0) {
+		if (r > 0) {
 			break;
 		}
 		bb_do_delay(LOGIN_FAIL_DELAY);
 		bb_info_msg("Login incorrect");
 	}
-	memset(cp, 0, strlen(cp));
-//	signal(SIGALRM, SIG_DFL);
 
 	bb_info_msg("System Maintenance Mode");